Double equals (Not equality) during assigning Java

Question

When I tried searching this I would just get things on equality.

When I was reading through some documentation for navigation in Android I had come across something I had never seen before. I came across this:

mTitle = mDrawerTitle = getTitle();

It almost looks like something you can do in JavaScript where you can take the first not-null variable and assign it to a variable.

In JavaScript I would do this:

mTitle = mDrawerTitle || getTitle();

And it would return the first not null, in Java, is this double equals usage the equivalent in Java?

What is this type of expression called?

This is known as chained assignment. – Oct 28 '13 at 03:21 — , Oct 28 '13 at 03:21

score 3 · Answer 1 · answered Oct 28 '13 at 03:14

3

Looking more into it, it is actually nothing like what I thought it was, it is simply the assignment operator.

You can assign a value to more then one variable at once using it.

For example:

int num = 20000;

int p, q, r, s;

p = q = r = s = num;

(Taken from the site)

answered Oct 28 '13 at 03:14

FabianCook

You can assign a value to more then one variable at once because the value of an assignment is the value that was assigned. Therefore you can use the value of an assignment as a rvalue of another assignment and so on. – MrSmith42 Oct 28 '13 at 11:01

1 Answers1